On September 27, the Intergovernmental Panel on Climate Change (IPCC), a UN organization consisting of climate change scientists, published the first of its three Working Group Reports of the IPCC's Fifth Assessment Report (AR5) on climate change. The 2000+ page long report from Working Group I, which consists of 258 experts, focuses on physical scientific aspects of the climate system and climate change, such as the impact of greenhouse gases and aerosols on the environment.

While the IPCC itself has hailed the report as an "alarm clock moment" for the world, it is dubious that everyone else feels the same, for three reasons:

That said, the tone of AR5's first Working Group Report is considerably stronger than its predecessors. Reuters called it the “strongest warning yet,” while the FT called it “a departure from the more cautiously worded findings in its past reports." (But then, as environmental James Delingpole says in his opinion in the Telegraph, "If there is one overriding prerequisite of every new IPCC Assessment report, it's to sound even more scary and urgent and certain than its predecessor.")

2. How much can we trust the report?

Between AR4 and AR5, there have been quite a few scandals that have severely undermined the authority and validity of the IPCC.

For instance, AR4 warned that Himalayan glaciers would disappear by 2035, which sparked a furor among environmental scientists. Georg Kaser of the University of Innsbruck in Austria, who led a different section of the AR4 process, said, "It is so wrong that it is not even worth discussing." The report also gave a wrong percentage for land in the Netherlands that was under sea level.

Critics accused the IPCC of "evasion of freedom of information law, secret deals done during the writing of reports ... a cover-up of uncertainties in the key research findings and the misuse of scientific peer review to silence critics."

That said, the IPCC has since learned its lesson. Climategate was "a turning point, a game-changer," according to climate change professor Mike Hulme of the University of East Anglia. Scientific research will be more open, and scientists more engaged with their critics and the public.

3. Who cares about the report, anyway?

The scientists have established the importance of human action to combat global warming. In light of the report, UN Secretary General Ban Ki-moon has called for an international summit in September next year to speed up the process, adding, “The heat is on, now we must act.”

However, even the co-chair of the AR5 group, Qin Dahe from China, said it was “impossible” that his own country, the world’s largest carbon dioxide emitter, would shut down the coal-fired powered plants that have fuelled its economic growth. He does, however, believe that the Chinese government has been driving up the use of clean energy in its industries.

Qin’s remarks have only served to further undermine the impact of the IPCC’s warnings and suggestions to policymakers, let alone to laypeople. Nevertheless, it is important that Ban’s calls for the summit next year be responded to; while dramatic decreases in a country’s use of fossil fuels may be unrealistic, small changes are better than none at all.

So now what?

The recent scandals that faced the IPCC and the discovery of the highly politicized nature of its findings — Delingpole paraphrases journalist Christopher Booker’s belief that IPCC reports are “essentially political artifacts rather than scientific ones” — have certainly been big hits to the IPCC’s credibility. It will take a lot for the organization to restore trust in the world, especially among those who are pessimistic about humans’ impact on climate change.